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60 lines
1.6 KiB
C++
60 lines
1.6 KiB
C++
// Formatting library for C++ - time formatting
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//
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// Copyright (c) 2012 - 2016, Victor Zverovich
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// All rights reserved.
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//
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// For the license information refer to format.h.
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#ifndef FMT_TIME_H_
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#define FMT_TIME_H_
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#include "fmt/format.h"
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#include <ctime>
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namespace fmt {
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template <>
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struct formatter<std::tm> {
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template <typename ParseContext>
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auto parse(ParseContext &ctx) -> decltype(ctx.begin()) {
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auto it = internal::null_terminating_iterator<char>(ctx);
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if (*it == ':')
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++it;
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auto end = it;
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while (*end && *end != '}')
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++end;
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tm_format.reserve(end - it + 1);
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using internal::pointer_from;
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tm_format.append(pointer_from(it), pointer_from(end));
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tm_format.push_back('\0');
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return pointer_from(end);
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}
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void format(const std::tm &tm, context &ctx) {
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buffer &buf = ctx.range();
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std::size_t start = buf.size();
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for (;;) {
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std::size_t size = buf.capacity() - start;
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std::size_t count = std::strftime(&buf[start], size, &tm_format[0], &tm);
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if (count != 0) {
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buf.resize(start + count);
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break;
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}
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if (size >= tm_format.size() * 256) {
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// If the buffer is 256 times larger than the format string, assume
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// that `strftime` gives an empty result. There doesn't seem to be a
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// better way to distinguish the two cases:
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// https://github.com/fmtlib/fmt/issues/367
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break;
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}
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const std::size_t MIN_GROWTH = 10;
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buf.reserve(buf.capacity() + (size > MIN_GROWTH ? size : MIN_GROWTH));
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}
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}
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memory_buffer tm_format;
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};
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}
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#endif // FMT_TIME_H_
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